Alarm device



Patented Apr. 26, 1949 UNITED STATES PATENT OFFICE Claims.

This invention relates to alarm devices. More particularly the inventionrelates to a film feed reel alarm.

It is customary to make up most motion pictures in several reels offilm. In order that the projection of the picture may be uninterrupted,due to the changing of the film reel, it is common practice to use twoprojectors alternately to show a complete picture. The object of thisinvention is to provide an alarm which will apprise the operator of themachine when a film reel is about to be exhausted of its film, so thathe can adjust the operation of the projectors alternately without anybreak in the projected picture.

Heretofore, devices for this purpose have been provided. Such devices,however, have not met with any great degree of commercial adaptationbecause they either required an electrical connection to effectoperation of the alarm mechanism at the proper time or their employmentresulted in undue noise much to the displeasure of the operator and tothose viewing the projected picture.

Therefore, it is an object of this present invention, in addition tothat of providing a simple and expeditious alarm for apprising theoperator just prior to the exhaustion of the film from the film feedreel, to provide the mechanism in a manner such that it will operatesubstantially noiselessly and with accuracy and the greatest degree ofefficiency.

Yet another and equally important object of the invention is theprovision of an alarm system for the purpose herein set forth, which maybe incorporated in the standard projecting machine without any materialchanges or alterations.

Other objects will appear hereinafter.

T he invention consists in the novel combination and arrangement ofparts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanyingdrawings showing the preferred form of construction, and in which:

Fig. l is a fragmentary side elevational View of a film reel andmagazine therefor, showing my improved film feed reel alarm associatedtherewith;

Fig. 2 is a fragmentary top plan view of the same;

Fig. 3 is a view similar to Fig. 1 showing the reverse side thereof andwith the gong striker in striking position.

It is desirable that the several objects of my invention be accomplishedby mechanism shown in its preferred form of construction in theaccompanying drawings and which mechanism will now be described.

In these drawings a magazine chamber is fragmentarily illustrated at l6.This chamber provides a suitable bearing l I through which is journaleda shaft 12. On this shaft I2 is arranged a feed reel i3 from which thefilm strip 14 is fed to a take-up reel (not shown). The shaft I2 carriesat one end portion a gear l5.

On the bearing l l is 2. depending bracket arm I6 carrying a plate H,the bracket arm l6 being secured to the bearing by set screws 16' or byany other suitable means. This plate at opposite end portions providesbearing plates 18 between which is rotatably supported a shaft l9. Thisshaft [9 is operatively connected to the gear l5 and is driven therebythrough the medium of a worm gear 2! On this shaft I9 is a governor 2|including arms 22 having weights 23 thereon. This governor 2| includes aflanged collar 24 movable longitudinally of the shaft 59 according tothe centrifugal action of the governor 2|.

On this plate [1 is a latch arm 25. This latch arm 25 is pivotallyconnected to the plate I! as at 25. The arm 25 has an angled end portion21 provided with a friction stud 28 adapted to engage the face 29 of theflanged collar 24.

The opposite end portion 30 of the latch arm 25 includes an adjustablelatch p-in 3| adapted to engage an arm 32 pivotally connected as at 33to the plate I? to maintain this arm 32 in a substantially verticalposition as shown in Fig. 1. To this arm 32 there is connected a hammer34. Extending from the plate I? is a supporting arm and carried at theupper end of this arm 35 is a bell or gong 35 so related with respect tothe hammer 3? as to be struck thereby when the hammer 34 is pivoted in aclockwise direction as viewed in Fig. 1, under the action of a spring37.

The latch arm 25 is normally urged into latchposition with respect tothe arm by means of a spring 33 (Fig. 3)

As the motion picture projector is operated in the customary manner, thefilm strip I4 is fed from the reel #3 to a take-up reel (not shown). Itis a known fact that with the film traveling at a constant speed throughthe projector the speed of rotation of the film reel [3 and shaft IEwill increase as the film strip it is unwound therefrom. This increasedspeed of rotation of the shaft 12 obviously increases the rotation ofthe shaft [9 and by reason of this increase in the speed of rotation ofthe shaft I9, the governor weights 23 will be thrust outwardly, movingthe flanged collar 24 relative to the fixed bearing 24' of the governor.This movement of the flanged collar 24 will pivot the latch arm 25 byvirtue of its engagement with the friction stud 28. This pivotalmovement of the latch arm 25 is against action of the spring 38, andwhen the latch arm 25 is thus pivoted the arm 32 will be pivoted to theright as viewed in Fig. 1 under the action of the sprin 31, bringing thehammer 34 into striking contact with the gong or bell 36, therebyapprising the operator of the motion picture projector machine of thefact that the film strip is about to be dispensed completely from thereel l3. Upon hearing the gong or bell 36, the operator then may preparefor operation the other moving picture projector machine or prepare todiscontinue the operation of the projector machine having the thusnearly spent film strip.

After the latch arm 25 has been pivoted in the foregoing manner torelease the hammer 34, the operator then resets the alarm by pivotingthe hammer 34 in a clockwise direction as viewed in Fig. 3, against theaction of the spring 31. This will dispose the lower end portion of thearm 32 in a position to allow the resetting of the latch arm by actionof the spring 38, that is, with the latch finger or pin 3| disposed inlatched engagement with respect to the lower end portion of the arm 32,thereby retaining this arm and the hammer in non-striking position untilthe speed of the shaft I9 causes the outward thrust of the weights 23,at which time the hammer 34 will then be released in a mannerhereinbefore set forth.

From the foregoing description, it is manifest that the releasing of thehammer 34 is by mechanism which is substantially silent in operation,thereby avoiding any disturbance until the hammer has actually engagedor struck the gong or bell.

The mechanism is effective and positive in operation and can bemanufactured at an economical cost. The device may be attached to anystandard motion picture projecting machine without any material changesor alterations therein.

In the drawings I have illustrated the spring 31 attached to the wallIll of the film reel housing. If desired, this spring 31 may be attachedto the usual door of the film reel housing so that when the door is openspring 31 will be expanded and the striker or hammer 34 will returnautomatically to its upright position as shown in Fig. 1.

While I have illustrated and describied the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modification without departing from the spirit of theinvention. I, therefore, do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaims.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

1. In combination, a mounting bracket, a variable speed shaft, a drivenshaft rotatably carried by the bracket and arranged substantially atright angles with respect to said speed shaft, 2. governor carried byand rotatable with the driven shaft and having a collar movablelongitudinally of said driven shaft, a worm gear connection between saidspeed shaft and said driven shaft, a bell supported by said bracket, ahammer adapted to strike said bell, means providing a pivotal connectionbetween said hammer and said bracket, latch means carried by saidbracket and adapted to releasably latch said hammer in a non-strikingposition with respect to said bell and including a member operativelyrelated to said collar whereby when said collar is moved in onedirection by said governor relative to said driven shaft said latchmeans will release said hammer for pivotal movement in a direction tostrike said bell, and means for moving said hammer into contact withsaid bell upon release of said hammer from said latch means.

2. In combination, a mounting bracket, a variable speed shaft, a drivenshaft carried by said bracket, driving connection between said speedshaft and said driven shaft, a governor carried by and rotatable withsaid driven shaft and having a collar mounted on said driven shaft formovement longitudinally with respect to said driven shaft by saidgovernor, a bell carried by said bracket, a hammer adapted to strikesaid bell, means providing a pivotal connection between said hammer andsaid bracket, latch means for releasably latching said hammer innon-striking position and having means operatively related to saidcollar whereby when said collar is moved in one direction longitudinallyof said driven shaft by said governor, said latch means will releasesaid hammer for pivotal movement in a direction to strike said bell, andmeans for moving said hammer into contact with said bell upon release ofsaid hammer from said latch means.

3. A film feed reel alarm including a shaft on which a film feed reel ismounted, a mounting bracket, a driven shaft rotatably carried by themounting bracket, means providing connection between the driven shaftand the film reel supporting shaft, a bell striker, means pivotallysupporting said striker from said bracket, a bell supported by saidbracket and adapted to be struck by said striker, latch means carried bysaid bracket for releasably latching the striker in nonstrikingposition, means controlled by the speed of said driven shaft foractuating said latch means to release said striker for movement intobell striking position, and means for moving said striker into contactwith said bell upon release of said striker from said latch means.

4. A film feed reel alarm including a shaft on which a film feed reel ismounted, a mounting bracket, a driven shaft rotatably carried by themounting bracket, means providing connection between the driven shaftand the film reel supporting shaft, a bell striker, means pivotallysupporting said striker from said bracket, a bell supported by saidbracket and adapted to be struck by said striker, latch means carried bysaid bracket for releasably latching the striker in nonstrikingposition, means controlled by the speed of said driven shaft foractuating said latch means to release said striker for movement intobell striking position, said last-named means including a centrifugallyactuated device carried by said driven shaft and movable longitudinallywith respect thereto and operatively related to said latch means toactuate said latch means to release said striker when said device ismoved in one direction relative to said driven shaft, and means formoving said striker into contact with said bell upon release of saidstriker from said latch means.

5. In combination, a film reel supporting shaft, a driven shaft arrangedsubstantially at right angles with respect tosaid' reel supportingshaft, means providing connection between said reel 5 supporting shaftand said driven shaft, a governor REFERENCES CITED on said driven shaftand including a slidable collar, alarm means including a pivotallysupported g igiig ggi ff are of record in the member, and latch meansadapted to latch said member in a predetermined position and opera- 5UNITED STATES PATENTS tively related to said collar whereby when saidNumber Name Date collar is moved longitiudinally of said shaft, said 3 9750 Edwards APR 3 13 latch means wil be operative to release said mem-2,123,084 Tanson July 5 193 her for pivotal movement, and means formoving said member into contact with said bell upon re- 10 FOREIGNPATENTS lease of said member from said latch means. Number Country DateWILLIAM C. HEINTZ. 21,762 Great Britain Sept. 22, 1910

